PlanetaryGearSet

Model ElementSpecifies a planetary helical gear set. Construction of (N + 2) Helical gears, which are the sun, the ring, and N planets.

Class Name

PlanetaryGearSet

Description

The planetary gear is defined by the following dimensions (see comments 11, 12, and 13):

The table below summarizes the attributes of the PlanetaryGearSet classes.

Variable	Type	Notes	Symbol
id	Int()	Unique identification number.
label	Str()	Descriptor of the gear set element.
rm	Reference("Marker", required=True)	The reference marker of the gear set element. This marker points to the center of sun and ring gear. Defines the orientation of the gear (z axis of the reference marker is the gear’s axial axis).
rm_2	Reference("Marker")	The reference marker of the first planet gear. This Marker needs to have the same orientation of the z-axis with the rm (axial direction), and its origin must be on the plane that is defined from the z axis of the rm (Inplane to the z axis of rm). The operating center distance is calculated from the two reference markers and is used as an input for the gear set (see comment 11).
module	Double(required=True)	The normal module of the gear.	$m_{n}$
number_of_planets	Int(3)	The number of planets of the gear set. Ensure that no planet interference occurs (see comment 11).	$N$
num_of_teeth_1	Int(required=True)	The number of teeth on the sun gear (see comment 12).	$z_{1}$
num_of_teeth_2	Int(required=True)	The number of teeth on gear 2 (see comment 12).	$z_{2}$
num_of_teeth_3	Int(required=True)	The number of teeth on gear 2 (see comment 12).	$z_{3}$
gear_ratio	Double(required=True)	The gear ratio between the ring and sun gear $z_{3} / z_{1})$ (see comment 13).	$u$
pressure_angle	Double(required=True)	The normal pressure angle in degrees.	$a_{n}$
helix_angle	Double(required=True)	The helix angle at the pitch diameter in degrees.	$β$
width_1	Double(required=True)	The width of the sun gear.	$b_{1}$
width_2	Double(required=True)	The width of the planet gear.	$b_{2}$
width_3	Double(required=True)	The width of the ring gear.	$b_{3}$
addendum_coefficient	Double(1.0)	The basic rack addendum coefficient.	$h_{a}^{*}$
dedendum_coefficient	Double(1.25)	The basic rack dedendum coefficient.	$h_{f}^{*}$
tool_tip_radius_coefficient	Double(0.38)	The basic rack tool tip radius coefficient.	$r_{f}^{*}$
hub_diameter_1	Double(0.0)	The inner diameter of the sun gear.	$d_{i 1}$
hub_diameter_2	Double(0.0)	The inner diameter of the planet gear.	$d_{i 2}$
hub_diameter_3	Double(0.0)	The outer diameter of the ring gear.	$d_{o 3}$
x1	Double(0.0)	The profile shift coefficient of the sun gear (see comment 6).	$x_{1}^{*}$
x2	Double(0.0)	The profile shift coefficient of planet gear (see comment 6).	$x_{2}^{*}$
x3	Double(0.0)	The profile shift coefficient of the ring gear.	$x_{3}^{*}$
j1	Double(0.04)	The circumferential backlash ratio of the sun gear. The range must be 0.03 – 0.05 (see comment 2).	$j_{1}^{*}$
j2	Double(0.04)	The circumferential backlash ratio of the planet gear. The range must be 0.03 – 0.05 (see comment 2).	$j_{2}^{*}$
j3	Double(0.04)	The circumferential backlash ratio of the ring gear. The range must be 0.03 – 0.05 (see comment 2).	$j_{3}^{*}$
g1_connection_part	Reference(“Part", required=True)	The part that is connected to the sun gear with a fixed joint.
g3_connection_part	Reference(“Part", required=True)	The part that is connected to the ring gear with a fixed joint.
carrier_part	Reference(“Part", required=True)	The part that the planet gears are connected to with a revolute joint constraint.
num_curve_segments	Int(10)	The number of mesh segments along the involute profile of each gear. When using a non-uniform mesh, this parameter is always an even number (the profile is split into two symmetric regions).
num_width_segments	Int(20)	The number of mesh segments along the width of each gear.
non_uniform_factor	Double(1.2)	Defines the factor of the mesh’s non-uniformity. The length of a triamesh element is equal to the previous element length times this factor. Use 1.0 for a uniform mesh.
density	Double()	The density of the gear's material (see comment 4).
contact_creation	Bool(True)	Activates an IMPACT contact between the two gears (see Contact IMPACT).
contact_stiffness	Double(1e5)	Specifies the stiffness parameter of the gear's contact (see Contact IMPACT `stiffness`).
contact_exponent	Double(2.1)	Specifies the exponent of the force deformation characteristic of the gear's contact (see Contact IMPACT `exponent`).
contact_damping	Double(1.0)	Specifies the maximum damping coefficient that is to be used for generating a damping force on the gear's contact (see Contact IMPACT `damping`).
contact_dmax	Double(0.1)	Specifies the penetration at which full damping is applied in the gear's contact (see see Contact IMPACT `dmax`).
contact_coulomb_friction	Enum("ON OFF DYNAMICS_ONLY", default="OFF")	Specifies the friction force model that is used to compute the gear's contact friction force (see Contact IMPACT`coulomb_friction`).
contact_mu_static	Double(0.2)	Defines the coefficient of static friction in the gear's contact when the friction is in the static regime (see Contact IMPACT `mu_static`).
contact_mu_dynamic	Double(0.1)	Defines the coefficient of the dynamic friction in the gear's contact when the friction is in the dynamic regime (see Contact IMPACT `mu_dynamic`).
contact_stiction_transition_velocity	Double(1.0)	Defines the slip velocity at which the static coefficient of friction, mu_static, is applied (see Contact IMPACT `mu_ stiction_transition_velocity`).
contact_friction_transition_velocity	Double(1.5)	Defines the slip velocity at which the dynamic coefficient of friction, mu_dynamic, is applied (see Contact IMPACT `mu_stiction_transition_velocity`).
export_graphic	Bool(False)	Exports the gears' geometries to two *.stl files. These files can be re-meshed in HyperMesh.
export_parameters	Bool(False)	Exports the calculated gear set and gear's parameters in a *.json file.

g = PlanetaryGearSet (
    id=1,
    label='Planetary gear set',
    rm=Marker(part=B_Ground),
    rm_2=Marker(part=B_Ground, qp=[center_distance, 0, 0], rm=rm),

    g1_connection_part=b_sun_shaft,
    g3_connection_part=b_ring_shaft,
    carrier_part=b_carrier_shaft,

    module=2.0,
    number_of_planets=3,
    pressure_angle=20.0,
    helix_angle=15.0,

    num_of_teeth_1=35,
    num_of_teeth_2=35,
    num_of_teeth_3=-103,
    gear_ratio=-2.943,

    width_1=20.0,
    width_2=20.0,
    width_3=20.0,

    addendum_coefficient=1.0,
    dedendum_coefficient=1.25,
    tool_tip_radius_coefficient=0.38,

    x1=0.07,
    x2=0.098,
    x3=-1.4288,

    j1=0.04,
    j2=0.04,
    j3=0.04,

    hub_diameter_1=0.0,
    hub_diameter_2=0.0,
    hub_diameter_3=0.0,

    num_width_segments=20,
    num_curve_segments=10,
    non_uniform_factor=1.2,

    density=7.85e-06,

)